A wireless communication terminal applied to CDMA (Code Division Multiple Access) communication starts a channel acquisition operation when sending or receiving a signal or when transferring data. Further, the wireless communication terminal obtains configuration information and timing information of the acquired channel and obtains position registration information etc. synchronized with the timing of the acquired channel.
In this regard, the received signal strength of this channel sometimes remarkably falls according to the environment (topography, buildings, etc.) in which the wireless communication terminal is used.
In a wireless communication terminal, when the received signal strength of the channel is low, regardless of the fact that the signal of the channel was received, the terminal judges that the channel could not be acquired and starts a restitute processing (a process to back to service area from no service area, or a process to re-acquire the other channel to back to the idle state). In this restitute processing, the wireless communication terminal runs a system scan where the terminal acquires a channel by a predetermined cycle.
When the wireless communication terminal is out of service area, the wireless communication terminal internally turns a flag showing it is “out-of-service-area” (out-of-service-area flag) ON. In such a situation, even if the user performs a send operation, the wireless communication terminal did not start up the send processing since the possibility of transmission was low while the out-of-service-area flag is ON and in general for saving power.
Further, once the terminal judged “out-of-service-area”, the terminal carries out the restitute processing by a predetermined cycle, but the communication schemes for running a system scan for reset are limited and the time required for restitute processing can no longer be ignored. For example, when exiting from or entering a tunnel or at another location where the usage environment is extremely different, desirably the restitute processing is carried out immediately after exiting from the tunnel. However, immediate reset is not possible unless at the timing of an restitute acquisition operation. Further, even if performing the restitute acquisition processing, this does not always lead to an immediate restitution into the service area.
In order to overcome the problem described above, the art is proposed of performing a channel acquisition operation if performing a send operation even when the terminal judged “out-of-service-area” (see, for example, Patent Document 1).    Patent Document 1: Japanese Patent Publication (A) No. 2003-23665